Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2020 Mar;62(2):224-231.
doi: 10.1002/dev.21865. Epub 2019 May 24.

Assessment of autonomic function in the late term fetus: The effects of sex and state

Julia H Zavala  1   2 , Lisa Ecklund-Flores  1   2 , Michael M Myers  2   3   4 , William P Fifer  2   3   4
Affiliations

Assessment of autonomic function in the late term fetus: The effects of sex and state

Julia H Zavala et al. Dev Psychobiol. 2020 Mar.

Abstract

Researchers have reported associations between fetal sex and heart rate (FHR) and heart rate variability (FHRV) but rarely in the context of fetal behavioral sleep state. We examined differences in measures of fetal autonomic function by sex and sleep state. Fetal abdominal ECG monitoring technology was used to measure FHR and two measures of FHRV-standard deviation of FHR (SD) and beat-to-beat variability (RMSSD). FHR and movement patterns were also recorded with standard Doppler ultrasound monitor technology employed to code sleep states. Data were collected from 82 healthy fetuses ranging from 36 to 39 weeks gestation. A one-way MANOVA showed that FHR was significantly lower and SD was significantly higher for males than females. Independent samples t tests found that these sex differences were only in the active sleep state. There were no significant differences in RMSSD by sex. Repeated measures MANOVA for a subset that exhibited more than one state (N = 22) showed that SD was significantly different by state. RMSSD showed a marginally significant sleep state difference. In conclusion, fetal sex differences in HR and HRV may indicate more mature autonomic functioning in near-term males than females and fetal sleep state can influence abdominal fECG derived measures of FHR and FHRV.

Keywords: fetal behavioral sleep states; fetal heart rate; fetal heart rate variability; fetal sex differences.

PubMed Disclaimer

Conflict of interest statement

Conflict of interest:

The authors have no conflict of interest.

Figures

Figure 1
Figure 1
Jpeg image. The top row is FHR and the second row is fetal movement. Dashed line indicates state change. Here the first state is 2F (frequent movements and high HRV) and the second state is 1F (infrequent movements and low HRV).
Figure 2
Figure 2
Main effect of Sex on FHR and SD (bars indicate +/− 1 SEM)
Figure 3
Figure 3
Effect of State and Sex on FHR and SD (bars indicate +/− 1 SEM)
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Amorim-Costa C, Costa-Santos C, Ayres-de-Campos D, & Bernardes J (2016). Longitudinal evaluation of computerized cardiotocographic parameters throughout pregnancy in normal fetuses: A prospective cohort study. Acta Obstetricia et Gynecologica Scandinavica, 95(10), 1143–1152. 10.1111/aogs.12932 - DOI - PubMed
    1. Arduini D, Rizzo G, Caforio L, Boccolini MR, Romanini C, & Mancuso S (1989). Behavioural state transitions in healthy and growth retarded fetuses. Early Human Development, 19(3), 155–165. 10.1016/0378-3782(89)90076-5 - DOI - PubMed
    1. Bernardes J, Gonçalves H, Ayres-de-Campos D, & Rocha AP (2008). Linear and complex heart rate dynamics vary with sex in relation to fetal behavioural states. Early Human Development, 84(7), 433–439. 10.1016/j.earlhumdev.2007.12.001 - DOI - PubMed
    1. Bhide A & Acharya G (2018). Sex differences in fetal heart rate and variability assessed by antenatal computerized cardiotocography. Acta Obstet Gynecol Scand, 9(12), 1486–1490. - PubMed
    1. Brändle J, Preissl H, Draganova R, Ortiz E, Kagan KO, Abele H, … Kiefer-Schmidt I (2015). Heart rate variability parameters and fetal movement complement fetal behavioral states detection via magnetography to monitor neurovegetative development. Frontiers in Human Neuroscience, 9(147), 1–8. 10.3389/fnhum.2015.00147 - DOI - PMC - PubMed

Publication types